It is known in the prior art to couple speed code signals and vehicle occupancy detection signals into running track rails for the movement control of transit vehicles by direct injection electrical connection directly into the running rails or into a low impedance shunt boundary connection between the rails and by magnetic coupling from an air core loop into one or more of the track rails such as described in U.S. Pat. Reissue Nos. 27,472 of G. M. Thorne-Booth and 3,746,857 of R. C. Hoyler et al.
The magnetic coupling loop has a relatively large area resulting in stray magnetic fields and the problem of signal cross-talk with parallel track rails.